LAUSR

Abstract This paper presented findings on statistical impact of mole fraction (x) on threshold voltage, on current, and off current in high-k/metal gate SiGe channel Tunnel FET (TFET) due to work function variability (WFV) of the metal gate. The analysis was carried out for varying mole fractions (x), average grain sizes, and device dimensions, using 3D TCAD device simulator. Our investigation showed that the fluctuation in threshold voltage (σVT) is noticeably affected by x, and grain sizes of metal gate. However, for large grain size, there is insignificant variation in σVT with an increase in x. Moreover, the distribution of threshold voltage is close to Gaussian for small grain size and bimodal for large grain size. The variation in on current (σIon) increases by negligible amount whereas off current fluctuation (σIoff) decreases significantly with increase in x. Further, the fluctuation in σVT with channel width is significant, but negligible with gate length.